Chair.



Patented J une 5, 1917 frz deze an www W15/dawg UNITED srnrns EDWARD W. HEDBERG,

or unicaen, ILLINoIs.

canin.

. Specification of ietters Patent. Patented J 11h05,

Application filled March 2, 1915. Seria! No. 11,529.

T0 all 'whom it may concern.'

Be it known that I, EDWARD W. Hnonne, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and use ful Improvements in Chairs, of which the following is a specification. l

This invention relates to chairs of the character used by barbers, dentists and others, wherein the 'seat of the chair is mounted for rotation and. also for up-anddown movement with relation to the base.

One of the objects of the invention is to produce improved means for moving the seat, by which thevertical niovementlof the seat, either rising or falling, may be stopped at any desired point to suit the operator.

Another object is to Simplify and improve the construction of chairs of this character. y In the accompanying drawings, Figure 1 is a view partially in side elevation and partially in central section illustrating a chair embodying the features of my invention. Fig. 2 is a horizontal section on a slightlyv enlarged scale taken in the plane of line 22 of Fig. 1. Fig. 3 is a section in the plane of line 3-3 of Fig. 1. Fig. 4 is a diagrammatic View illustrating the manner of electrically connecting the switch con`- tacts, the motor and the circuit loreakeisthe latter being shown in detail in this (view.

4I will herein describe the preferred ernbodiment of my invention, but it should be. understood that I do not thereby intend to limit myself to the precise details of construction shown in the drawings, but aim to include all modifications falling withinthe scope of my invention 'as defined in the appended claims.

.The chair comprises a base which is shown as composed of three parts, to-wit, the lower flaring part 5 which' rests upon the floor, an upper outer tubular part 6 resting on said lower part, and an inner tubular guide oicylinder '7 positioned centrally within the part 6, the lower-end extendinginto a central opening in the lower part 5 and hav ing a flange Swhich rests on said lower art. At the upper end of said tubular guice is an outwardly and downwardly extending Harige 9 which telescopes over the upper end yof the outer part (i. j

l.Within the tubular guide? isa coperating tubular post or plunger 10 which ie vertically slidable, said plunger having a flared `wish of the with the plunger upper end 11 which is rigidly secured tothe underside of the seat 12 ofthe chair. A vertical screw-threaded shaft 13 is located. within the plunger 10, being rota-- tahle'in .a bearing 14 in said plunger and having-ball-bearing collars 15 xed thereon above and below said bearing. On the upper end of this shaft is fixed a bevel pinion 16 which meshes with a bevel pinion 17 fixed on or connected to the armature shaft 'of a motor 18, which is suitably fixed to the underside of the chair seat. This motor is of the reversible type and is adapted to be run in opposite directions to raise and lower thev seat, as will he presently explained.,

The lower end of the shaft 13 is threaded into a bearing-member 19 which maybe of .inverted U shape, the shaft passing through the base of the U and the arms of the U` ex'- tending downwardly and being bent outward at their lower ends which rest upon the bottom ofthe tubular guide 7 ofthe base. The upper end of this hearing meniber is adapted to be received in the lower end of the plunger 10 and said member is arranged to give or yield to' prevent any binding ofthe parts. y

'Rigidly fixed on the lower end of the screw shaft 13 concentric therewith is a vcircular head 20. Itwill be understood thatv the screw shaft moves up and down 4along 10 and the chair seat,y and at the upper and lower limits of movement of these parts the head 2O is carried into engagement with a pair of circuit breakers to be presently described. Y Tljie electric current to drive the motor 18 1s supplied through a cable or conduit 21, part of the wires therein being attached to two pairs of contacts. and 23 which are mounted upon and insulated from the lower end of the tubular guide T. A foot lever 2l is pivotcd at 25.1510 swing in afhorizontai plane, one elul of said lever passing throi'lgh slots 2G in the base elements and lnivin'g its outer end upturued or twisted to facilitate engagement ot' the lever by the operators foot. The iuu'cr end of the lever is forked topi-ovule two arms which are adapted to bridge the respective pairs of contacts 'x22 and 23. nected by suitable wires; iu. the manner indicated iu Fig. ifwilh the motor 1S through two circuit breaker, devices 2T and 28 as previously mentioned Thesetuo devices are;

These pairs of contacts are con iixed tothe iin-ferfwall of .the'tubularguide i 7 at a point below the lowermost position of the plunger 10 and respectively above and below the head 20 on the screw shaft 13, as shown in Fig. l. Each of said devices comprises a body havin an opening therein in which a switch ymem er 29 is vertically slidable, said member having. a pin-andslot connection 30 with the body and being normally pressed outwardly by a coiled spring 31. Two lugs 32 iiXed respectively on the body and the switch member are arranged to contact with each other when the switch is in its outermost position. The opening in the bodyis 'lined with insulating material so that the switch members 29 cannot come into electrical contact with the body except throu h the lugs 32.

Re erring more specifically to the manner of wiring these parts, as shown in Fig. 4, the reference numeral 33 indicates an ordinary llamp socket which constitutes the source of power, said socket being connected with one of the contacts 22 and 23 and the motor. One of the contacts 22 is connected directly to the. socket and its complementary contact is connected to the switch member 29 of the upper circuit breaker, the body of the latter being connected to the motor, so that when the switch member 29 is in its normal position the circuit will be complete when the lever 24 bridges the contacts 22. The other pair o'f contacts 23 are connected respectively to the socket and to the switch member of the lower circuit breaker, the body of the latter being connected to the motor. The motor armature terminals are c, c and (Z. Terminal a is connected to the lamp socket 33 through the normally open foot switch contacts 22, the normally closed travel limit switch 27 and the lead e. The terminal c is similarly connected to the lamp socket 33 through the contacts 23, the other limit switch 28 and the lead f. Termiuals and d are connected directly to the lamp socket through the leads g' and 7L, re-

spectively. Within the motor the terminals t and d may be connected together as shown at i and each terminal a, and c is suitably connected to on'c end of the armature winding as shown in Fig. 4. Thus when the foot lever 24 is in contact with the pair of contact pieces 22, the motor armature 18 will be driven in a clockwise direction to elevate the chair seat since the current flows through the armature inone direction, and when the lever 24 is in engagement with the other pair of contacts 23, the motor armature will be driven in a counter clockwise direction to lower the seat, since the current iows through the armature in the opposite direction with respect to the iield flux of the motor for the direction of the field current Iand consequently that of the field flux remains unchanged. Herein, I have not rent flowing therein is not to be reversed.

It may be directly connected to the lampsocketv 33 or any other suitable source of energy as. desired. A pair of springs 34 acting on the lever tend to hold it in` its central or neutral position in which 1t 1s 1n en-l gagement with none of the contacts.

It will thus be seen that when the operator wishes to raise or lower the chair seat, it isonly necessary for him to horizontally swing the lever 24in one direction or the other, with his foot and remove his foot when the chair has'come to the desired elevation. In case the operator should forget to remove his foot before the seat has reached the limitof its travel, the circuit breakers 27, 28 would act to break the circuit and stop the motor, so that no damage to the parts would be occasioned.

I claim as my invention:

1. The combination of a part to be raised and lowered, a plunger rigid therewith and extending downwardly, a base having a tubular guide in which said plunger fits slidably and rotatably, a vertical screw-shaft longitudinally in opposite directions as a.

unit when said shaft is rotated in opposite directions, a circuit for said motor, a switch device in the circuit for controlling the motor, a member mounted on the end of said shaft and, longitudinally slidable therewith, and a pair of circuit breakers in said motor circuit in series with and independent of said switch device and mounted on the inner wall of said tubular guide below the lowest position of said plunger and arranged to be operated by s id member at the extremities of movements of the first-mentioned parts for stopping the motor.

2. The combination of a..base having a vertical tubular guide,l a part having a vertical plunger slidable in said guide, a vertical screw-threaded shaft positioned within said ,plunger and mounted to travel therewith, a bearing on the base in which said shaft is threaded, a reversible motor carried by sa-id part and connected to said shaft, the said part, plunger, motor and Ashaft moving vertically together as a unit, a circuit fork said part, a switch device in series with said circuit breakers and independent thereof in series with said circuit breakers for controlist It. is hereby certified that in Lettere Patent No. 1,2234, granted June 5, 1917, upon the application of Edward W. Hedberg, oi Chicago, Illinois, for an improvement in Cheb-s," an error appears in the printed specification reqtiinng orrecton as follows: Page 2, lines 129-130, claim 2,.etrke ou-t the words in series with said circuit breakin-5"; and that the said Lettere Patent shouid be reed with this correction therein that the me may eonorm to the record of the eene in the Patent Ofoe.

Signed and sealed this 26th dey of June, A. D., 1917.

R. F. WHITEHEAD,

Acting C'ommoner of Pahala.

leen.) 

